The present invention relates to an exhaust-gas collecting and cleaning device for a multi-cylinder engine, comprising an exhaust-gas manifold constructed as a casting and an exhaust-gas cleaning device mounted near the engine, attached to the exhaust-gas manifold and comprising a housing and at least one exhaust-gas cleaning element bedded therein. According to an independent further aspect, it relates to an exhaust-gas device for a multi-cylinder engine, comprising an exhaust-gas manifold constructed as a casting and an exhaust-gas guide element mounted near the engine and attached to the exhaust-gas manifold.
An exhaust-gas collecting and cleaning device according to the introduction is known from European Patent Application 0761939. The purpose of mounting the exhaust-gas cleaning device close to the engine is to favor its heat-up behavior, or in other words to shorten the time needed for effective exhaust-gas cleaning to develop after the engine is started. In the known exhaust-gas collecting and cleaning device according to the introduction, the exhaust-gas manifold and the inlet funnel as well as the jacket of the housing of the exhaust-gas cleaning device form a structural unit, in that they are constructed as a one-piece casting. An outlet funnel constructed as a sheet-metal part is welded onto the jacket of the housing of the exhaust-gas cleaning device.
The known exhaust-gas collecting and cleaning device of the type according to the introduction suffers from a large number of considerable disadvantages: In particular, the combined casting for exhaust-gas manifold and inlet funnel as well as jacket of the housing of the exhaust-gas cleaning device is complex and therefore expensive to make. The heavy weight or large mass of each cast unit is also a disadvantage, not the least with respect to the heat-up behavior of the exhaust-gas cleaning device. Furthermore, a welded joint is provided between the jacket of the housing of the exhaust-gas cleaning device constructed as a casting and the outlet funnel constructed as a sheet-metal part; such a welded joint is also complex and expensive because of the unavoidable requirements (especially choice of specific material and preheating of the casting, use of a specific welding wire).
From the disadvantages associated with the prior art, the present invention derives its basic object which consists in further developing an exhaust-gas collecting and cleaning device of the type according to the introduction to the effect that simple and inexpensive manufacture is possible in combination with light weight.